Process of obtaining resin extracts from coal



Oct. 5, 1943. H. HIGGINS 2,330,887

I PROCESS OF OBTAINING RESIN EXTRACTS FROM COAL Filed May 20, 1940 Patented Oct. 5, 1943 PROCESS or OBTAINING RESIN EXTRACTS I FROM COAL Ernest H.;Higgins, Salt Lake City, Utah Application May 20, 1940. Serial No. 336,081

3 Claims.

This invention relates to 'the obtaining of resinous extracts from carbonaceous mineral substances, such as coal.

Resinous substances are relatively inexpensive, hence any method for obtaining resinous extracts from coal must be capable of being carried on at a very low expense.

One of the objects of this invention is to pro vide a method for this purpose, which is very simple, and which can be carried on with very simple apparatus.

A further object of the invention is to provide a solvent which is capable of dissolving the resinous constituents in the carbonaceous mineral, and at the same time to provide a step in the method which will enable substantially all of the solvent to be recovered from the coalafter the principal portion of the solvent has been run off.

A further object of the invention is to provide a simple and inexpensive method for obtaining resinous extracts from a'carbonaceous mineral such as coal, and to obtain as a by-product, oils similar to pine oils.

A further object of the invention is to provide steps in practicing the, method, which will result in producing clarified resin and heavier oil or heavier resins resulting from the practice of the process after the solvents have been driven off.

I have found it advantageous to filter the resinproduce an emcient process of obtaining resinous I tion of the invention, it. should be stated that solvents such as kerosene and gasoline, acetone, carbon tetrachloride, and chlorinated solvents, were employed with generally unsatisfactory results. Alcohols were also employed, but all of these solvents produced resins of little value, or the loss by absorption was too great to enable them tobe employed. As a result of these experiments I discovered that turpentine had admirable qualities for this purpose, as its use in the process would result in producing resins of good quality. However, it would be impossible to employ turpentinefor this purpose if it were impossible to recover a large proportion of the turpentine employed in the process. Finally, after conducting many experiments, I discovered that by the use of a second solvent such as kerosene or gasoline, a large proportion of the turpentine could be recovered. In performing theseexperiments it was found that a large portion of, the turpentine could be recovered by employing a mixture of the turpentine and kerosene or gasolineas a solvent for the resinous constituents in the coal, but the use of this mixture did not compare favorably with thesuccessive use of turpentine and kerosene, for the reason that when the mixture of turpentine and kerosene was employed, a very considerable quantity of the turpentine would remain in the treated coal, whereas in the, other case I discovered that by following the turpentine treatment with a treatment by kerosene or gasoline, substantially all the turpentinecan be recoveredfrom the treated coal. This is an important factor in my process,

because it enables the process to be carried on very economically, and the coal after being treated, becomes improved as a combustible.

The use of the second solvent operating to extract the remaining turpentine in the coal and an extra percentage of-resinous material, makes this process of commercial value.

One of the diftlcultiesencountered concerns the color of the resin or gum, and it became necessary to provide means for improving the color of the liquid resin. In connection with this matter, the

but an intermediate product, and seems to be a product'that is new to commerce.

In my'attempt to improve the co1or,'I found that filtration through clays and carbons was beneficial. Filtration through fullers earth had I prefer to use fullers earth in a dry state, and alternate the V 7 same with layers of bleaching powder, and employ a final layer of fullers earth through which the solvents pass after passing through the alternating layers of fullers earth and bleaching powder, by placing screens between the separate layers so that the fullers earth could be recovered and used again.

In practicing myiprocess, I have found that the use of; an. oxidizing agent is also most advantageous as affecting the yield of pine oil" which isderived as a by-product by final distillation of the resinso'lvents after the turpentine and the'kerosene have'been driven off in distilling the same to recover the resins. It was found that by using bleaching powder as an oxidizing'agent, the recovery of pineoil was increased to-about 15%; also by treating with bleaching powder and dilute acid, and mixing, from 40% to 45% oil is produced.

My process can be carried on by the useof any suitable apparatus which will enable the turpentine to come into intimate contact with the carbonaceous mineral or coal. In the present instance by way of example, I have illustrated 'a simple apparatus consisting of a container I of cylindrical form into which the coal is placed. It is preferable to have this coal in a more or less finely divided state, but no extreme division of the coal seems to be necessary. I practiced my process successfully by reducing coal to size, which would run through a screen of about onehalf inch mesh. However, the reducing of the size of the coal merely tends to change the time consumed in practicing the process. Suificient time should be allowed for the turpentine to enter all the pores of the coal and thoroughly saturate the same, sufficient time being allowed to effect the dissolving of the resinous constituents. i

Referring to the drawing, 2 represents the coal whichis charged into the container! through'a charging opening 3 in the upper head 401 the cylinder.

In practicing the process, I fill the. container l with turpentine to a level approximately at the line 5 so that the coal is completely submerged in the turpentine. No heat is necessary in carrying on the process. The turpentine is? permitted to cover the coal for approximately twenty-four hours, after which it is run off through a drain connection 6 in the bottom of the tank or 0on tainer. After running off the turpentine I then fill the container with kerosene tosubme'rge the coal, the purpose of the kerosene being to act as a solvent. for'the turpentine. In' dissolving this turpentine it also recovers from the coal a considerable percentage of resinous ingredients, thereby giving adouble advantage involving not only an increased amount of resin product, but also reducing the cost ,by reducing the loss of turpentine in carrying on the process.

As an example of my process, I used thirty-two pounds of coal crushed to size of about one-half inch and less, and this coal was placed in the container and submerged in two gallons (7,500

i increase of 980 cc., indicating that the 940 cc. of

turpentine that had remained in the coal, was now dissolved in the kerosene. This result was confirmedalso by a distillation test which I made.

The turpentine which I prefer to employ in conducting my process, is 360 F., and the starting point of the kerosene employed is 400 F.

In practicing my process after draining off the two solvents, turpentine and kerosene, they shouldv be distilled. In the example of my process given above, the kerosene mixture started to pass over at about 304 F., and about was distilled off before a temperature of 360 F. was reached.

Instead of employing kerosene, gasoline having I an end point of 300 F. may be employed. When using gasoline, the recovered turpentine was passed over in the distillation process after the gasoline had all distilled off.

In distilling the solvent turpentine, and the solvent kerosene or gasoline, I continue the distillation after substantially all of the turpentine or kerosene has passed over to the condenser, and after this I collect the distilled products separately, one of which consists of a pine oil of -fine quality.

In order to clarify the resinous products and also to increase the yield of an oil resembling pine oil, I employ an oxidizing agent in the solvents before they are distilled. This may be accomplished by providing filter materials in the drain 6, which have been already referred to as preferably including fullers earth. In the present instance I have illustrated a layer or charge I of fullers earth above a screen 8. Valves l0 and II may be employed respectively, above and below the filter material for controlling the rate of flow through the same. This will remove the coal dust. After this the resinous extracts should be run through the bleaching powder and again through fullers earth if desired. The distillation of the solvents to recover the resinous ingredients and the pine oil, is preferably carried on with steam as commonly employed in distilling processes, although of course, the distilling may be carried on without steam, if desired. This pine oil is evidently a product of the oxidation of the resin solution, for I found that a similar treatment ofthe solvent without employing the oxidizing agent, does not produce the pine oil. The bleaching'powder treatment, however, resulted in a lO to 15% production of pine oil and with the bleaching powder and acid the production is increased to 40. to 45% of the volume of extract.

In addition to conducting the distillation of the solvents both dry and with steam, I have also employed vacuum distillation, and in each case theoil was present at the end ofthe distillation. This pine oil has been subjected to exhaustive tests and has been pronounced to be suitable for flotation work, and equal in some respects to standard pine oil. I have used the pine oil to form a paste with carnauba wax to produce a high class polish which can be used on automobiles, furniture and floors, being very easy to apply, and giving a hard lustrous and lasting finish.

The container I may be provided with a side opening for discharging the coal.

The term coal used in this specification, means a black, or brownish-black solid, combustible mineral, formed by the partial decomposition of vegetable matter without free access of air, under the influence of moisture, pressure and temperature.

Many other embodiments of the invention may be resorted to without departing from the spirit of the invention.

What I claim is:

1. A process of obtaining resinous extracts from coal, which consists in treating the coal with turpentine to dissolve the resins in the coal, draining on the turpentine from the coal, treating the said coal thereafter with kerosene to recover the turpentine remaining in the coal and the rest of the resins, distilling off and recovering the turpentine and kerosene thereafter by distillation to leave the resins.

2. A process of obtaining resinous extracts from coal, which consists in covering the coal with turpentine for a suflicient time to substantially dissolve most of the resinous constituents in the coal, draining off the turpentine from the coal thereafter, covering the coal thereafter with kerosene to recover the turpentine and other resins remaining in the coal after the said draining off of the turpentine, and thereby forming a solution composed of the kerosene and the tin"- pentine remaining in the coal, and distilling off and recovering the turpentine and kerosene thereafter to leave the resins.

3. A process of obtaining resinous extracts from coal, which consists in confining the coal in a semi-granular state, submerging the coal under turpentine for substantially twenty-four hours to dissolve the resinous constituents in the coal, draining 01f the turpentine from the coal, submerging the coal thereafter in kerosene to recover the turpentine with any dissolved resins remaining in the mineral substance, and distilling ofi the turpentine and kerosene thereafter to leave the resins.

ERNEST H. HIGGINS. 

